If the price exceeds 3% (excluding 3%), the buyer can choose to refund the purchased commercial house more or make up less. If the Buyer chooses to return the house, the Seller shall refund all the payment and interest within 30 days upon the Buyer's written application for return the house (from the date of payment to the date of refund, calculated according to the bank's fixed asset loan interest rate for the same period on the date of refund).